1. Field of the Invention
This invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device with a relatively large screen for use in liquid crystal television sets, liquid crystal projectors, personal computers and the like.
2. Description of the Related Art
Getting larger in size, recent liquid crystal display panels have found their applications as a display in liquid crystal television sets or liquid crystal projectors. For the operation mode, such liquid crystal display panels often use the STN mode because of the high contrast, rather than the TN mode conventionally in common use.
It is well known that as the number of scanning lines increases due to larger panel sizes, the liquid crystal contrast decreases.
One method to avoid this problem, as disclosed in Published Examined Japanese Patent Application No. 52-199960, is that the select time for each scanning electrode is doubled by dividing the signal electrodes of the liquid crystal display panel into two groups, upper and the lower groups, and making a parallel drive of each group.
With this technique, the voltage margin in driving the liquid crystal can be increased and the contrast can be raised. Theoretically, the larger the number of divisions, the higher the contrast. From a manufacturing viewpoint, however, the maximum number of divisions is two, preventing further improvements in the contrast.